Project Summary/Abstract CANDIDATE My immediate goals are to continue my research and training in electrophysiology, biological imaging and neuroscience. During the K99 phase (2 years), I will conduct experiments and be trained in electrochemical recording methods and multi-photon imaging. I will publish papers and search for a job as an independent faculty/investigator during the K99 phase, and will transition to the R00 independent phase (3 years) upon securing a faculty position. The total duration of the project is 5 years. ENVIRONMENT The K99 phase of this project will be conducted at the California Institute of Technology, which affords an excellent research and learning environment for postdoctoral scientists. Caltech has a strong neuroscience community, excellent faculty, and many highly productive and resourceful postdoctoral scholars and graduate students for one to collaborate with. Caltech also runs the Biological Imaging Center through the Beckman Institute, a resource that will be a very important part of my training plan. For the institution where I will conduct my R00 phase studies, I will choose an institute or university with excellent neuroscience resources and faculty that will put me in the best position for growth and success. RESEARCH This research program is designed to test the hypothesis that specific nicotinic ACh receptors are important for modulating release of neurotransmitters such as dopamine. In particular, I will test the idea that nicotinic receptors containing [unreadable]6 subunits, which are found on dopamine presynaptic terminals, are important mediators of dopamine release. I will also test the idea that the ability of these receptors to mediate dopamine release is governed by their subcellular regulation by the neurons where they reside. Finally, I will test the idea that [unreadable]6 receptor expression and function are significantly altered when animals are exposed to chronic nicotine. Thus, these experiments will determine whether these receptors are important in dopamine release and in disorders such as nicotine dependence. To carry out these experiments, I designed and built a set of novel transgenic mouse lines to particularly isolate aspects of [unreadable]6 nAChR biology. For example, some experiments will utilize mice with hypersensitive [unreadable]6 receptors that amplify and isolate [unreadable]6 physiology and behavior, while other experiments will make use of mice expressing fluorescently-labeled [unreadable]6 receptors that allow for direct visualization of these proteins in live neurons.